Finite temperature ab initio calculated thermodynamic properties of orthorhombic Cr3C2

Abstract Due to severe discrepancies between reported Gibbs energies of formation we calculate the thermodynamic properties of orthorhombic Cr 3 C 2 ab initio in an attempt to resolve the experimental scatter. All relevant excitation mechanisms are considered, including the T =0 K formation energy, electronic entropy and quasi-harmonic and anharmonic vibrations. We find that derivative quantities of the free energy, such as isobaric heat capacity and relative thermal expansion are well described by this approach, serving as a benchmark for the calculations. Comparison shows that the final ab initio Gibbs energy has a less steep temperature dependence than what has previously been obtained by assessment.